Find the common difference of the arithmetic sequence. −16,−7,2,11

Abby is preparing fruit punch for her party. she starts with a bowl filled with liquid that has 1/2 fruit juice and 1/2 sprite, but she decides it's too fruity. so she pours out 1/4 of the liquid, and then fills the bowl up again with sprite. what fraction of the punch is now sprite?

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

Ineed someone to me answer my question i have to have this done and knocked out